Improvement in wood-screws



UNITED STATES PATENT OEEICEci ANDBEWJB. LIPSEY, OF WEST HOBOKEN., NEW JERSEY IMPROVEMENT IN wooo-semaws.A

Specilcation forming part of Letters Patent N0. 112,935. daf-6d March 2l, 1571- o @ZZ-whom, it may concern) Be it known that I, ANDREW B. LIPsEY, of Vest Hoboken, in the county of Hudson and State of 'lNew Jersey, have invented certain newand useful Improvements in Heads for Screws; and I do hereby declare the following to be a full, clear, and exact description of the same, reference being had to the accompanying drawings, in which* Figure l represents a screw-head made in accordance with my invention as it appears when inserted in wood. Fig. 2 represents a central section of my improved headoas applied to a wood-screw. Fig. 3 represents the splitting eiiect of the ordinary'screw-head when inserted in wood.

The nature of my invention consistsin form- I ing a sharp lip or flange around the lower outside part oi the head, as hereinafter described.

In the drawings, the part marked A is the body ofthe screw, and B is the head. The under side of the head B is made concave or recessed, so as to leave a sharp lip, c, around the lower corner of the head, as indicated in Figs. l and 2. The lip or flange c cuts into the wood C when the screw is used, and kprevents the head from pressing the fibers apart and splitting the wood, as is done by the ordinary conical head, the appearance of which is illustrated in Fig. 8, where D is the screwhead, and E the wood. The ordinary conical head also presses down the iiber of the wood, so as to leave a depression around the head unless the wood has previously been removed by countersinking, whereas with myimproved head the lip'a cuts the bers at the outer corner of the head, 'and none of the fibers are pressed down,except such portions as are under the head, the remainder being left iiat and smooth, as shown' in Fig. l, and that, too, without the labor` or trouble of countersink The thread d of the screw may be made in the ordinary man-ner, and the slot f in the head, by which the screw is turned, may also be cut entirely across the head, or only for a portion ol' the distance, as desired. A

Having described my improved head for screws, what I claim therein as new and of my invention, and desire to secure by Letters Patent, is-

A wood-screw one endof which is provided with a thread, d, and the other end with a head, B, having a slot, f, for turning it,'and

an under lip or flange, c, substantially as and for the purposes set forth.

' ANDREW E. 'LIrsEY.

Witnesses:

WILLIAM G. QUIGLEY, NATHAN T. MADDEN. 

